State separation for virtual applications

ABSTRACT

Application states may be stored and retrieved using policies that define various contexts in which the application is used. The application states may define configurations or uses of the application, including connections to and interactions with other applications. Applications that are virtualized may have state that is defined within a usage context and multiple states or configurations may be stored and recalled based on the usage context. Policies may define the context and what parameters are to be saved, and may be applied when applications are operated in a virtualized manner.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and benefit of U.S. patentapplication Ser. No. 12/181,315 filed 28 Jul. 2008 entitled “StateSeparation for Application Changes” by John M. Sheehan.

BACKGROUND

Applications can be modified in many different manners. In some cases,an application may be modified by updating registries, changingconfiguration files, updating dynamic linked libraries, or othermechanisms. Each change to the application may affect portions of anoperating system, which may in turn affect other applications

SUMMARY

Application states may be stored and retrieved using policies thatdefine various contexts in which the application is used. Theapplication states may define configurations or uses of the application,including connections to and interactions with other applications.Applications that are virtualized may have state that is defined withina usage context and multiple states or configurations may be stored andrecalled based on the usage context. Policies may define the context andwhat parameters are to be saved, and may be applied when applicationsare operated in a virtualized manner.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a diagram illustration of an embodiment showing a system forstoring different configurations based on the context of an application.

FIG. 2 is a flowchart illustration of an embodiment showing a method foroperating with different context configurations.

DETAILED DESCRIPTION

Applications may be operated in different states or configurations. Onesuch mechanism is through application virtualization. When anapplication is configured for a particular context, the configurationinformation may be saved and recalled for later use. The application maybe configured to operate in many different states and a set of policiesmanage the configurations.

The state in which an application is executed may include operatingsystem configurations, the presence and operation of various otherapplications, the configuration of services accessed over a network orother connection, and many other factors. The configuration andoperation of the application may be different for different states.

For example, some applications may have a symbiotic relationship withother applications. The behavior or performance of an application on itsown may be different from the behavior or performance of an applicationwith another integral application. In such an example, a configurationmay be defined for the application in the state of solo operation, and aseparate configuration may be defined for the application when thesecond symbiotic application is present and operating.

In a typical embodiment, applications may be operated in a virtualenvironment. The virtual environment may be capable of acceptingdifferent sets of configuration settings based on a particular context.In some cases, a virtual environment may be a virtual machineenvironment. In other cases, a virtual environment may be a virtualapplication environment.

For the purposes of this specification and claims, an applicationconfiguration may refer to the way an application is set up orconfigured. An application configuration may include any element thatmay be changed or set, including those elements that affect theperformance, functions, look, or other operational characteristics ofthe application.

For the purposes of this specification and claims, an application statemay refer to the context in which an application is executed. The statemay include an operating system and any settings or configurations ofthe operation system or any applications installed or executing. Thestate may include the condition and configuration of any other elementthat may interact with the application, including hardware components,services available over a network, other executing applications,peripheral devices, and any other item.

For the purposes of this specification and claims, an applicationcontext may be a category of an application state. While the state mayinclude any variable that may affect an application, a context may be abroad category that may be used to classify and store a configuration.For example, contexts may be defined for sessions, virtual applicationenvironments, virtual machine environments, user specific contexts,machine specific contexts, user group or machine group specificcontexts, contexts where two or more interacting applicationsinteroperate, and other contexts.

Throughout this specification, like reference numbers signify the sameelements throughout the description of the figures.

When elements are referred to as being “connected” or “coupled,” theelements can be directly connected or coupled together or one or moreintervening elements may also be present. In contrast, when elements arereferred to as being “directly connected” or “directly coupled,” thereare no intervening elements present.

The subject matter may be embodied as devices, systems, methods, and/orcomputer program products. Accordingly, some or all of the subjectmatter may be embodied in hardware and/or in software (includingfirmware, resident software, micro-code, state machines, gate arrays,etc.) Furthermore, the subject matter may take the form of a computerprogram product on a computer-usable or computer-readable storage mediumhaving computer-usable or computer-readable program code embodied in themedium for use by or in connection with an instruction execution system.In the context of this document, a computer-usable or computer-readablemedium may be any medium that can contain, store, communicate,propagate, or transport the program for use by or in connection with theinstruction execution system, apparatus, or device.

The computer-usable or computer-readable medium may be, for example butnot limited to, an electronic, magnetic, optical, electromagnetic,infrared, or semiconductor system, apparatus, device, or propagationmedium. By way of example, and not limitation, computer readable mediamay comprise computer storage media and communication media.

Computer storage media includes volatile and nonvolatile, removable andnon-removable media implemented in any method or technology for storageof information such as computer readable instructions, data structures,program modules or other data. Computer storage media includes, but isnot limited to, RAM, ROM, EEPROM, flash memory or other memorytechnology, CD-ROM, digital versatile disks (DVD) or other opticalstorage, magnetic cassettes, magnetic tape, magnetic disk storage orother magnetic storage devices, or any other medium which can be used tostore the desired information and which can accessed by an instructionexecution system. Note that the computer-usable or computer-readablemedium could be paper or another suitable medium upon which the programis printed, as the program can be electronically captured, via, forinstance, optical scanning of the paper or other medium, then compiled,interpreted, of otherwise processed in a suitable manner, if necessary,and then stored in a computer memory.

Communication media typically embodies computer readable instructions,data structures, program modules or other data in a modulated datasignal such as a carrier wave or other transport mechanism and includesany information delivery media. The term “modulated data signal” means asignal that has one or more of its characteristics set or changed insuch a manner as to encode information in the signal. By way of example,and not limitation, communication media includes wired media such as awired network or direct-wired connection, and wireless media such asacoustic, RF, infrared and other wireless media. Combinations of the anyof the above should also be included within the scope of computerreadable media.

When the subject matter is embodied in the general context ofcomputer-executable instructions, the embodiment may comprise programmodules, executed by one or more systems, computers, or other devices.Generally, program modules include routines, programs, objects,components, data structures, etc. that perform particular tasks orimplement particular abstract data types. Typically, the functionalityof the program modules may be combined or distributed as desired invarious embodiments.

FIG. 1 is a diagram of an embodiment 100 showing a system with a stateseparation and management system. Embodiment 100 is an example of asystem that may store and manage configurations for an application basedon the context or state of the application.

The diagram of FIG. 1 illustrates functional components of a system. Insome cases, the component may be a hardware component, a softwarecomponent, or a combination of hardware and software. Some of thecomponents may be application level software, while other components maybe operating system level components. In some cases, the connection ofone component to another may be a close connection where two or morecomponents are operating on a single hardware platform. In other cases,the connections may be made over network connections spanning longdistances. Each embodiment may use different hardware, software, andinterconnection architectures to achieve the functions described.

Embodiment 100 is an example of the functional elements that may make upa multi-state execution system for an application. Differentconfigurations 104 of the application 102 may be executed in anexecution system 106 based on the context in which the application is tobe executed.

Various embodiments may have different levels of configurations that maybe executed for an application. For example, an application that isinstalled and executed within an operating system environment may have aset of configuration files that define a configuration. A different setof configuration files may be used to launch the application 102 basedon the context associated with the configuration files.

In another example, an application may be executed within a virtualenvironment and, in addition to the configuration files of the previousexample, registry settings, dynamic linked libraries, and many otherconfiguration elements may be varied between contexts. Such virtualenvironments may be virtual machine environments or virtual applicationenvironments. When a virtual environment is used to execute anapplication, a very broad and rich set of configuration elements may bevaried between contexts.

An application 102 may be any type of executable program or set ofprograms, services, or other operations that are performed within acomputing environment. In many cases, an application may have acollection of executable elements such as files that may be executeddirectly within an operating system environment or executed within anapplication environment, such as scripts, subroutines, libraries, orother components.

Many applications 102 may operate in conjunction with other applicationsor services. For example, an application 102 may operate with a webservice that is accessed over the Internet. In such an example, theapplication may perform some operations and the web service may performother operations in order to deliver a user experience.

In another example, an application 102 may be operable on its own orwith another application that ‘plugs in’ or is at least partiallyintegrated with the first application. An example may be an applicationsuch as a word processing program that may display a toolbar, menuitems, or other links to a document publishing application when thedocument publishing application is operational. When the documentpublishing application is not available, the word processing applicationmay have one user interface, but may have a second user interface andsecond set of functions available when the document publishingapplication is available.

In such an example, the application 102 may have one configuration 104defined for a state or context when operating alone, and a secondconfiguration 104 defined for a second state or context when operatingwith a second application. Each configuration 104 may be separatelydefined and managed using a change monitoring system 108 in conjunctionwith a set of policies 110.

The change monitoring system 108 may detect and store changes to anapplication configuration 104. The change monitoring system 108 maydetect a change, classify the change, and determine if the change isapplicable to one or more contexts in which the application 102 isexecuting or will be executed. The definitions of how the changes andcontexts are classified and how the changes are dispositioned may bedefined in the policies 110.

Embodiment 100 shows a separate application 102 and a set ofconfigurations 104. In some embodiments, the configurations 104 may bestored as a set of files or settings that may be implemented on top ofdefault configurations that may be defined within the application 102.In such embodiments, the configurations 104 may be viewed as a ‘delta’file or group of changes from the default.

In other embodiments, an application may be defined as a package thatincludes one of the configurations 104. A different application packagemay be created for each configuration. Such embodiments may be usedwhere the settings within a configuration are pervasive or where theconfiguration changes are used when the application is started. Anexample of such configuration changes may be registry settings thatdefine options used by the application during initial startup.

The execution system 106 may be any environment, workspace, or mechanismcapable of executing the application 102. In some embodiments, theexecution system 106 may be an operating system environment in whichmany other applications and services operate, including the changemonitoring system 108, for example. In some embodiments, the executionsystem 106 may be a virtual environment such as a virtual machine or avirtual application environment. In still other embodiments, theexecution system 106 may be a separate hardware platform that executesthe application 102.

The architecture of the embodiment 100 may be any type of computingarchitecture. In some embodiments, many of the components illustrated inembodiment 100 may be executed on a single hardware platform such as apersonal computer or server computer. In other embodiments, some of thecomponents may be performed on one hardware platform while othercomponents may be performed on a separate hardware platform. Some suchembodiments may use many different hardware platforms to implement theembodiment 100. Such embodiments may be termed a cross machineconfiguration.

In some cross machine architectures, some of the components ofembodiment 100 may be implemented as virtual machines or operated withinvirtual application environments. A virtual machine may be a softwaresimulation of a hardware platform and may contain an operating systemand may function as if the virtual machine were a separate, dedicatedhardware platform.

Application virtualization may create application-specific copies of allshared resources. Each application may have a separate configuration ofpotentially shared resources such as registry entries, dynamic linkedlibraries, and other objects that may be packaged with the application.The package may be executed in a cache, creating a virtual application.When a virtual application is deployed, it may use its own copy of theseshared resources.

A context manager 112 may determine a context in which an application isoperating or will be operating. The context manager 112 may monitor thepresence, configuration, and other parameters of many differentresources that may be available for the application 102. The contextmanager 112 may determine a state for an application that may be used bythe change monitoring system 108 to store configurations appropriately.The context manager 112 may also define a state for an applicationlauncher 126 which may select between the various configurations 104based on the state or context.

The context manager 112 may be an application or service thatcontinually monitors various facets of a system. In some cases, such acontext manager 112 may operate on a single hardware platform andmonitor various conditions. The hardware platform may be the samehardware platform on which the application 102 may be executed. In otherembodiments, the context manager 112 may be a service that operatesremotely from the hardware platform on which the application 102 isexecuted.

The context manager 112 may collect various information, metadata, andparameters about the state in which an application is being operated orwill be operated. The context manager 112 may collect any pertinentinformation that may be used within the policies 110 to handleconfigurations in different manners. Different embodiments may collectdifferent sets of information and metadata to determine a current state.

Examples of contextual metadata may include what virtual applications114 are present or not present, the presence of various virtual machines116, the presence and configuration of an operating system 118, thepresence and configuration of various other applications 120 and networkservices 122, as well as other state information 124. Other stateinformation may be a session in which an application is operated,membership in a group of users or devices, or other parameters.

The other state information 124 may include information about a session,which may include metadata about a session. For example, the stateinformation 124 may include the type of session, which may be a sessionconnecting two or more specific devices or users, or a sessionconnecting two or more general devices or users. The session metadatamay also include various connection parameters, such as the protocolsused within a session or the addresses or ports used to establish asession. In some embodiments, an application may create severaldifferent types of sessions with other applications or services, and thepresence, absence, or configuration of the sessions may be defined aspart of the context for the application.

The presence and configuration of other interactive components maydefine a part of the context for an application. The application 102 mayinteract with virtual applications 114, virtual machines 116,applications 120, and network services 122 in different capacities. Insome cases, the performance or operation of an application may beaffected by the presence, absence, or configuration of variousinteractive components external to the application 102.

The presence, absence, and in some cases the configuration of acomponent with which an application interacts may define a new state foran application. For example, an application may add or remove userinterface components for other applications or services. When anotherapplication is present and configured, a first application may provide acertain set of user interface components or functionality that link toor use functionality provided by the other application. When the otherapplication is not present or configured differently, the firstapplication may present an alternative user interface or functionality.

A component with which the application interacts can be a virtualcomponent. In some cases, an application may be executed virtually usingthe execution system 106 while another application may also be executedvirtually. Because both applications are executed virtually, eachapplication may operate without interacting with each other in a defaultconfiguration. However, when both applications are operational, eachapplication may be configured to pass data, control, or other signalsbetween each application. In such a case, each application may have adesignated configuration 104 that defines the interaction points andenables the interaction to occur, even when both applications areoperated virtually and separately. In such a case, both applications maybe launched simultaneously or sequentially with the properconfigurations so that the applications may interact.

The virtual components may present different configuration options thancomponents that are installed and operating within the same operatingsystem as the application 102. In general, virtual components mayoperate agnostically to other components and may be configured inparticular manners to interact with other applications in separateenvironments, including conventional operating system environments orother virtual environments.

A context may include various parameters or configurations of anoperating system 118. For example, a context may include generalinformation about an operating system, such as the type of operatingsystem, the specific version, and other parameters about the nativeoperating system. A context may also include additions or changes to theoperating system environment, such as registry settings, the presenceand configuration of files such as dynamic linked libraries, settingsused by the operating system to access various hardware peripheraldevices and interfaces, and any other type of parameter.

In some embodiments, the configurations 104 may be applied when anapplication is launched. Some embodiments may also enable aconfiguration 104 to be applied to an application 102 after theapplication begins execution.

Some embodiments may enable some configurations 104 may be able to beapplied after beginning execution while other configurations 104 mayonly be applied when an application starts. In such embodiments, two ormore configurations 104 may be applied to a single instance of anapplication 102. For example, a company-wide configuration may bedefined that sets company-wide default settings for an application. Asecond configuration may be applied that contains user-specific settingsthat may or may not further adjust the company-wide configuration for auser's personal preferences.

In another example, an application 102 may interact with several otherapplications or network services. Each network service or applicationmay be defined within a separate configuration 104 so that when theapplication 102 is started, many different configurations 104 may beapplied, each enabling a separate application or service to be accessed.

An application 102 may also interact with various network services 122that may be available over a local area network (LAN), wide area network(WAN), or any other network, including the Internet. In many cases, aweb service may be used to provide data in response to queries and otheroperations or services. A configuration 104 may be defined for executingthe application 102 when the web service or other network service 122 ispresent. Such a configuration may include various parameters such asports, protocols, addresses, and other communication configurationinformation, as well as configuring specific functionality to beavailable through the application 102.

The configuration 104 may include user interface components, links, orother configurable items that may enable a network service 122 to beaccessed in certain instances.

For example, a word processing program may use a thesaurus service thatis provided as a network service 122. When the thesaurus service isavailable, the word processing program may have links to the thesaurusservice in the user interface, such as a menu selection for accessingthe thesaurus service. When the thesaurus service is selected, a querymay be sent to the network service and a response received. The responsemay be displayed within the word processing program as if the thesaurusservice were part of the word processing program. In such a case, a usermay not realize that a network service was invoked. When the thesaurusservice is not available, the configuration 104 may substitute a localversion or may make a thesaurus function inactive, invisible, orotherwise inaccessible.

The context manager 112 may define a context within which an applicationis currently operating or intended to be operated. The context may beused in conjunction with the policies 110 to create a specificconfiguration 104 that may be recalled when an application launcher 126starts the application 102. The context manager 112 may also detect acurrent context that may be used by the application launcher 126 toselect the appropriate configuration 104 or group of configurations 104.

The context in which an application executes may be defined by thepolicies 110. A context may be a classification or type of state. Inmany cases, a state may have several contexts. For example, anapplication 102 may interact with another application operating on avirtual machine 116 as well as interact with a network service 122. Thepresence of a virtual machine 116 may define a virtual machine contextand the presence of network services may define a network enabledcontext. In some cases, two or more different contexts may apply.

When multiple configurations 104 may be applied to a single instance ofan application 102, multiple independent contexts may be defined for aspecific instance. In the example above, a virtual machine context and anetwork enabled context may be defined separately and independently.

When a single configuration 104 may be applied to an instance of anapplication 102, a context may be defined that is the conjunction ofseveral different factors. In the example above, a single context may bedefined that includes a virtual machine and network enabled services anda single configuration 104 may be created. Separate configurations maybe created for a virtual machine without the network enabled servicesand for network enabled services without the virtual machine.

The policies 110 may define the type of context and how changes to anapplication configuration are to be handled based on the context. Forexample, some changes may be discarded while other types of changes maybe stored. When multiple independent configurations are used, a policymay define one type of change to be stored in one context but notanother.

FIG. 2 is a flowchart illustration of an embodiment 200 showing a methodfor operating with context dependent configurations. Embodiment 200 isan example of various operations that may be performed by the componentsof embodiment 100, including an application launcher 126, a contextmanager 112, a change monitoring system 108, and an execution system106.

Other embodiments may use different sequencing, additional or fewersteps, and different nomenclature or terminology to accomplish similarfunctions. In some embodiments, various operations or set of operationsmay be performed in parallel with other operations, either in asynchronous or asynchronous manner. The steps selected here were chosento illustrate some principles of operations in a simplified form.

Embodiment 200 illustrates a method for launching an application,detecting changes to the configuration of the application, and storingthe changes in a configuration store for later reuse.

A command may be received to launch an application in block 202. In manycases, a command may be initiated by a user input such as selecting anicon or entering a command on a command line. In other cases, a commandto launch an application may be initiated by another application orservice, including a network service.

The context for the application may be determined in block 204. Thecontext may be defined in a policy and sets of configuration parametersfor the application may be created for specific contexts. The contextmay be determined by any manner. In some embodiments, a context managersuch as context manager 112 in embodiment 100 may be used to determinethe current or intended context.

The context may be a current context or an intended context. A currentcontext may be determined by sensing the current state of variousparameters, systems, and services with which an application mayinteract. An intended context may be a context that may exist when theapplication is executing.

An intended context may be used when several applications that mayinteract with each other are launched in succession or substantiallysimultaneously. Each application in the group of launched applicationsmay be configured to operate with the other applications, but such acontext may exist when all of the applications have been started andhave made connections with each other.

If there is no configuration defined for the context in block 206, adefault configuration may be selected in block 208. If a configurationis defined for the context in block 206, the configuration may be loadedin block 210.

In some embodiments, two or more configurations may be loaded andapplied based on the context. In such embodiments, variousconfigurations may be applied in succession, with the last configurationapplied being able to overwrite a setting of a previous configuration.

Some embodiments may apply a priority scheme to determine whichparameters of which configuration may be applied when more than oneconfiguration sets a parameter. In a succession priority scheme, thelast configuration applied may dominate. However, in other schemesdifferent metrics or rules may be applied. Such rules may be defined ina set of policies.

Once the configurations are defined, the application may be executedusing the configurations in block 212.

In many embodiments where multiple configurations are used, theapplication may be executed in a virtual environment, such as adedicated virtual machine or within an application virtualizationenvironment. By virtualizing an application, many settings may bechanged or configured in an easier manner than if the application wereoperating within a conventional operating system environment with manyother applications. For example, a virtual environment may enableregistry settings or dynamic linked libraries that may otherwise beshared with another application to be changed for the virtualapplication.

If a change is detected in block 214, a process may begin for creatingor modifying a configuration setting based on the context of theapplication.

The context may be classified in block 216. In some embodiments, aspecific instance may include several different contexts, each havingone or a small number of parameters that may be independent from othercontexts. In other embodiments, a single context may be defined for anysituation that may contain many different parameters or descriptors. Aset of policies may define the contexts.

The change may be classified by type in block 218. The change type maybe a general classification of the change as defined in a policy so thatthe change may be dispositioned appropriately.

For each context classification in block 220, the change may bedispositioned in the following blocks. Embodiment 200 is an example ofan embodiment where two or more contexts may exist for a particularsituation. In other embodiments, a single context may be defined and thefor-loop of block 220 may be performed a single time for the context.

If the policy does not specify how the type of change is handled inblock 222, a default policy may be applied in block 224. Otherwise, thecurrent policy may be applied.

The current policy or default policy may state whether the change is tobe saved or disregarded in block 226. If the change is to be disregardedin block 226, the change may not be stored in block 230. If the changeis to be saved in block 226, the configuration may be updated for thecontext in block 228.

The process may continue in block 220 for the next context, if oneexists. When each of the contexts has been processed in block 220, theprocess may return to block 212 for further execution of theapplication.

Embodiment 200 is an example of a process that may be used to determinea context and save a change to an application based on the context. Whenan application is restarted in the same context, the configuration maybe recalled and the application may behave in conformance to the change.

The foregoing description of the subject matter has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the subject matter to the precise form disclosed,and other modifications and variations may be possible in light of theabove teachings. The embodiment was chosen and described in order tobest explain the principles of the invention and its practicalapplication to thereby enable others skilled in the art to best utilizethe invention in various embodiments and various modifications as aresuited to the particular use contemplated. It is intended that theappended claims be construed to include other alternative embodimentsexcept insofar as limited by the prior art.

What is claimed is:
 1. A method comprising: executing a virtualapplication on a first device, said virtual application having a firstconfiguration and a first state, said virtual application including aplurality of resources, the plurality of resources including a secondapplication; detecting a change to said virtual application, said changedefining a second state, said change affecting at least one of saidplurality of resources; determining a first context for said secondstate, said first context not being a user context or a machine context;and storing said change based on said first context.
 2. The method ofclaim 1, said first context comprising a session specific context. 3.The method of claim 1, said first context comprising a cross machinecontext.
 4. The method of claim 3, said cross machine context comprisingat least one virtual machine.
 5. The method of claim 1, said secondapplication being a virtual application.
 6. The method of claim 1, saidvirtual application being executed on a first hardware platform, one ofsaid resources being executed on a second hardware platform.
 7. Themethod of claim 1, at least one of said plurality of resources being ina second virtual context.
 8. The method of claim 7, said first contextbeing an application virtualization context.
 9. The method of claim 8,said second virtual context being an application virtualization context.10. The method of claim 8, said second virtual context being a virtualmachine context.
 11. The method of claim 6, said first context being afirst virtual machine context.
 12. The method of claim 1 furthercomprising: starting said virtual application; determining a currentcontext for said virtual application; referencing a policy defined forsaid current context; determining that said current context includessaid first context; and operating said virtual application using saidchange.
 13. The method of claim 1 further comprising: starting saidvirtual application; determining a current context for said virtualapplication; referencing a policy defined for said current context;determining that said current context does not include said firstcontext; and operating said virtual application without said change. 14.A hardware system comprising: an execution system configured to executea first virtual application in a plurality of contexts, said firstvirtual application including a plurality of resources, the plurality ofresources including a second application; and a change monitoring systemconfigured to: determine that a change has been made to said firstvirtual application, said change affecting at least one of saidplurality of resources; determine at least one context for said change;and store said change such that said change may be implemented when saidat least one context is a current context.
 15. The system of claim 14,said plurality of contexts comprising at least one of a group composedof: a session specific context; a session type specific context; a crossmachine context; and a dual application context.
 16. The system of claim14, said said resources said second application selected from among agroup composed of: a second application operating in a virtualapplication context; a second application operating in a virtual machinecontext; and a second application operating on a separate hardwareplatform.
 17. A method comprising: executing a virtual application on afirst hardware platform, said virtual application having a firstconfiguration defining a first state, said virtual application includinga plurality of resources, at least one of said plurality of resourcesbeing executed on a second hardware platform; detecting a change to saidvirtual application, said change defining a second state, said changeaffecting at least one of said plurality of resources; determining atleast one first set of contexts for said second state, said first set ofcontexts including at least one context other than user context andmachine context, said first set of contexts comprising at least onevirtual context; referencing a policy defined for at least a portion ofsaid first set of contexts; and storing said change based on said atleast a portion of said first set of contexts as defined in said policy.18. The method of claim 17, said at least one virtual context comprisingat least one of a group composed of: a virtual application context; anda virtual machine context.